Question: The lifespans of seals in a particular zoo are normally distributed. The average seal lives $13.8$ years; the standard deviation is $3.2$ years. Use the empirical rule $(68-95-99.7\%)$ to estimate the probability of a seal living between $7.4$ and $17$ years.
Solution: The probability of a particular seal living between $7.4$ and $17$ years is ${13.5\%} + {68\%}$, or $81.5\%$.